353. Falco island us. 23 in.

Adults in perfect plumage, pure white, slightly barred on the back and spotted below with black.

Nest. - Of sticks, lined with grasses and feathers; placed on ledges of cliffs; eggs bulky white, specked with reddish brown, often so thickly that the ground color is obscured (2.30 x 1.80).

Range. - Arctic region, breeding in Northern Greenland, and wintering to the Gulf of St. Lawrence, and casually to northern Maine.